First and foremost I look at Road Runner cartoons especially the earlier cartoons from the 1940's. Later into the 1950's the backgrounds in all Hollywood cartoons became more simple, stylized and UPA like. Even though I like those backgrounds very much I felt these more realistic backgrounds are better suited to our project. Most of these pictures come from the Road Runner cartoon "Fast and Furryous", as seen on Youtube.
The other animation I research was the movie Home on the Range. This, the last Hand-Drawn Disney animated movie has wonderful backgrounds, that really evoked the American Mid-West. It also shows that deserts can be quite colourful with blue cactus and purple grasses, so we can have fun with the colour scheme. Here is a clip from the movie.